There is a whole host of information that can be gathered about the crash from the autopsies of the victims. The details are pretty morbid, but the information could be critical.
Though it tends to become news fodder it is really a key part of the investigation. See the link below regarding AA587 as an example of the information gained.
Victim Fragmentation Patterns and Seat Location Supplements Crash Data: American Airlines Flight 587 | Amy Mundorff - Academia.edu